Reaktion #66371

Reaktionsgleichung

ammonium chloride

6-(3-Nitrophenyl)-7-pyridin-4-yl-pyrazolo[5,1-b]thiazole

NaHCO3

→

3-(7-pyridin-4-yl-pyrazolo[5,1-b]thiazol-6-yl)-phenylamine

Ausbeute 68.6%

Lösungsmittel

dioxane water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with ethyl acetate (3×20 mL)
2. 2
   WaschenCombined organic layers were washed with sat. aq. NaHCO3 and brine
3. 3
   Trocknendried over Na2SO4
4. 4
   Einengenconcentrated under reduced pressure
5. 5
   SonstigeThe crude product was purified by chromatography on silica gel (DCM/MeOH 97:3)

Vorschrift

6-(3-Nitrophenyl)-7-pyridin-4-yl-pyrazolo[5,1-b]thiazole (410 mg, 1.272 mmol) was dissolved in a 3:1 dioxane/water mixture (8 mL). Zinc powder (333 mg, 5.094 mmol, 4 eq) and ammonium chloride (680 mg, 12.72 mmol, 10 eq) were added and the mixture was stirred at 100° C. for 2 hours. It was then diluted with water, made basic by addition of saturated aqueous NaHCO3 and extracted with ethyl acetate (3×20 mL). Combined organic layers were washed with sat. aq. NaHCO3 and brine, dried over Na2SO4 and concentrated under reduced pressure. The crude product was purified by chromatography on silica gel (DCM/MeOH 97:3) to give 255 mg (68%) of 3-(7-pyridin-4-yl-pyrazolo[5,1-b]thiazol-6-yl)-phenylamine as white solid.

Quelle